| From: Jan Beulich <jbeulich@suse.com> |
| Subject: x86/paging: don't unconditionally BUG() on finding SHARED_M2P_ENTRY |
| |
| PV guests can fully control the values written into the P2M. |
| |
| This is XSA-251. |
| |
| Signed-off-by: Jan Beulich <jbeulich@suse.com> |
| Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> |
| |
| --- a/xen/arch/x86/mm/paging.c |
| +++ b/xen/arch/x86/mm/paging.c |
| @@ -274,7 +274,7 @@ void paging_mark_pfn_dirty(struct domain |
| return; |
| |
| /* Shared MFNs should NEVER be marked dirty */ |
| - BUG_ON(SHARED_M2P(pfn_x(pfn))); |
| + BUG_ON(paging_mode_translate(d) && SHARED_M2P(pfn_x(pfn))); |
| |
| /* |
| * Values with the MSB set denote MFNs that aren't really part of the |